Burner unit



March 28, 1939.

R. JOHNSON BURNER UNT 'I' Filed Mal'` 18. 1956 m d n .O 5 .n .In O Wd wQIJH MNO. 2 9:2 L. .A ,In B w B L .1/ F f l/O 2 l onthelineI-i'" of 'InPatented Mar. 2s, 193e UN1T1-:D six-friasl PATENT OFFICE My inventionlrelates to `the burner unit of an l overfeed type of coal stoker, andwould ordi-v narily be associated withV automatic feeding means toconstitute an automatic stoker.

5 fuel employed will usually be coal, although my invention is not to belimited' to the use of coal alone, as other materials may be'burned inthis unit or mingled with the coal'.

Burners have generally been made of cast iron Y or like metal, fgr thereason that lthe cast ironA resists`- distortiony and burning out' whensub# jected to the heat of. the ilre, and does not tend to cause theformation of clinkers. Cast iron construction, however, is relativelyexpensive inv the shape necessary for such burners. It is one of theprincipal objects" of this invention to provide a burner structure whichprimarily by the use of structural steel shapes and steel plate can bewelded together, and can be assembled cheap# ly,'yet effectively, andwhich is provided, if need be, with cast iron elements which can be verycheaply made, to be used at points where the :tire would tend to burnout or cause clinkers if of steel construction, so that. the wholeburnermay be produced less expensively and at least as quickly andconveniently as a cast burner unit.- Itis a further object toincorporate in such a 'A burner unit, as the principal element thereofand the one which 'gives lt its principal strength;

- a piece of structural steel shape. such as "an 40 I n the accompanying`have shown my inventiony in an illustrative f orm asnowpreferredhymen"lFigure 1 is a plan view 45 FigureZisalOnglhldialsectlonthrough me, line2121-22-19! 55. air' chamber beneath itpreferably by a pan 'or The" c Itls desirablethat the fue] be permitted t0 l the" 5 'The has ofthernaywel-I bea box 2, formed to extend beneath the web I0 an `Welded theretoas indicated at n. If desired, the

upper flanges and web of an I-beam shape might constitute the flanges Il and web In, respectively, and the downwardly ,projecting flanges would5 form a support for the fuel chamber I 5 and sides for the air chamber2|. 'I'he box 2 itself may be ofcorner welded construction, cut fromsheet steel, or, where an I-beam shape is used, the sheet steel wouldform the bot-tom and ends of the l0 box. This, in conjunction with theweb I0, constitutes an air chamber 2|. The hearth is provided with slits30 constituting grate apertures. Since it is desirable to employ a castiron grate, coal tending to clinker and l5 Y stick to a steel grate, itis preferred that Aa. large 'sperme 12 nush with the upper surface ofthe 20 we b Il. To this end cleats I3 may be welded to the underside ofthe web at two opposite edges of the aperture l2. By removing the grate3 the air chamber 2| may becleaned out when necesspread somewhat by thetime it reaches the flre. Itis delivered from a fuel supply pipe 5 byany suitable means which advances it therealong to deliver it upon theupper surface of the web lll; 30 for example a worm 5l may be employed.The pipe. 5,.then, is connected to the Vend of the burner opposite thegrate I, and to form a fuel'chamber I5 for the spread of the fuel and toconne gases distilled from Vthe coal and to force them through theburning massi Ipneferably provide a hood Il of inverted U-shape form incross s ection, which may be made from a structural channel shape,resting upon and welded at I9 to the upper edges of the flanges Il, andextending in- 40 ward to a point adjacent the grate 3. 'Ihe fuel chamberIl is completed by anend p late I 6 which is-welded across the end ofthe-channel I and of the hood Il, suitably apertured for the receptionofthe fuel pipe .l and' an airisupply pipe i. '45

' Since-the stoker is of thel overfeed type,the opposite end ofthe fuelchamber Il is left open for discharge of ashes therefrom over the edge.of the web II.

Air for combustlonis supplied preferably under 50 pressure through theair supply pipe 6, which connects with the air chamber 2|. This pipe,which for simplicity and cheapness 'should be round, is shown asofsomewhat larger diameter l than the height of the air chamber 2|, andsimi- 55 larly the fuel supply pipe is somewhat greater in diameter thanthe height of the fuel chamber Il. In order to accommodate these pipes,which are welded in place in the end plate I6 of the 5 burner unit, orin the end of the pan 2, the web l Il is swaged, as indicated at I'I, toaccommodate the fuel pipe, vrand at I8 to accommodate the air Dipe- 'Ihecoal piles up, over the grate 3. to a level 10 somewhat axacent theupper surface of the hood I I. It must be prevented from spilling overthe edges of the flanges and upon the hood, and itV is undesirable thatthe steel parts be subjected to the direct heat of the nre. I thereforepreferably provide an apron I which surrounds or encircles the re on atleast three sides. As the gases, distilled by the heat of the fire 'fromthe fresh fuel behind the grate 3 and beneath the hood Il, emerge abovethe-flanges Il and over the front edge of the hood I4, they areconstrained by-the apron 'l from escaping unburned in directionslaterally outward from the top edges of the fuel and combustionchambers, but instead are directed up through the burning top layer offuel and the heated zone thereabove.

Such gases are there burned, increasing the efiiciency of combustion,instead of being wasted. Furthermore, the iire is rendered moreeffective by being directed, by the apron I, upward as a concentratedcolumn of intensely hot flame instead of spreading outward over agreater area. This upstanding. apron is of cast metal, and rests uponthe upper edges of the flanges II inwardly of the end of the hood Il,and upon the inner end 0f the hood itself. 'Ihis piece may be 5 insertedthrough-the ash door ofa furnace, for

example, and the apron 'I may be put in place after proper installationoi.' thel main burner unit. In manufacture the shape I may be cut intosultable lengths with facility, and the remaining parts are of simpleconstruction and the welding of' these parts together is very easily andcheaply accomplished. As a result not only is the burner strong andsturdy and long lasting, but it Vis inexpensive and readily installed.

55 What I claim as my invention is:

1. A burner unit for automatic stokers comprising a length of steelchannel disposed horimentally, and having a web forming a hearth, andupstanding flanges, and apertured' in' its w web adjacent one end, acast grate removably received in said aperture, a box welded beneath theweb, constituting an air chamber communieating with the grate aperture,an air supply pipe discharging into said air chamber, a hood 5 coveringthe top of the channel end remote from the grate aperture end, andwelded to the longitudinal flange edges, a fuel supply pipe deliveringfuel upon the hearth beneath the hood for advance towards the grate, anda cast apron extending upward from the edges of the channel flanges,outside of the hood, and from the edge of the hood adjacent thereto.

2. A burner unit for automatic stokers comprising a length of steelchannel disposed horizontally and having a web forming a hearth, andupstanding flanges, a hood covering the top of one end of said channeland welded to the longitudinal iiange edges, to define a fuel chamber,the web of the uncovered channel'end having grate aperturestherethrough, a fuel supply pipe to deliver fuel to the covered end ofthe fuel chamber, a box underlying and welded to the channel andconstituting an air4 chamberv communicating with the grate apertures, anair supply pipe to deli'ver air to the air chamber, and a. cast apron ofU-shape extending upward from the uncovered edges of the two flanges andthe adjacent edge of the hood, to retain the live coals, to confine thegases distilled from the unbumed coal, and to direct the flame upward ina column. y

V3. The combination of claim 2, wherein the fuel supply pipe is ofgreater diameter than the height of the hood above the channel's web,and the air supply pipe is of greater diameter than the air chamber, theweb being downwardly and upwardly swaged, respectively, to receive saidDIPGS. t

4.' A burner unit for automatic stokers of the overfeedtype,jco`mprising a hearth having an l unobstructed edge constituting adischarge end for passage of ashes thereover, its opposite endconstituting a fuel feed end, side walls integral with said hearth andupstanding from opposite sides thereof, a hood covering a portion ofsaid hearth and the adjacent portions of the side walls at the feed. endthereof, a grate in said hearth, outside of the hood, a fuel supplyconduit to deliver fuel to the feed end of 'said hearth and beneath saidhood, and a U-shaped apron of a size to seat upon the uncovered portionsof said' side walls and that edge of said hood which is remote from thesupply conduit, and extending upwardly well above said hood and sidewalls.

' 5. A burner unit for automatic stokers of the overfeed type,comprising a. hearth having an unobstructed edge constituting adischarge end for passage of ashes thereover, its opposite endconstituting a feed end, a grate in said hearth, an air supply conduitcommunicating with the space beneath said grate, sidewalls upstandingfrom opposite sides of said hearth, a hood covering the feed end of saidhearth and the adjacent and that edge of said hood which is remote from,

the Vfuel supply conduit, and extending upwardly well above said hoodand side walls.

' ROY JOHNSON.

